Types of special support surface Air mattress

This either replaces or is placed on top of a standard hospital bed mattress. They provide minimum reduction in contact pressure but should be considered as minimum support for any patient with the above factors.

Low air loss bed

These purpose-built pressure-relieving beds allow easier patient mobility than other support surfaces. Contact pressure may still be higher than capillary occlusion pressure so positioning is still required. Patients who are haemodynamically unstable should usually be managed on a low air loss bed, particularly if receiving vasoconstrictor drugs. The presence of pressure sores with intact skin is an indication for a low air loss bed. Rotational low air loss beds allow automated lateral rotation at variable time intervals to facilitate chest drainage. These may also be useful where manual positioning is impractical.

Air fluidised bed

This is the only support surface that consistently lowers contact pressure to below capillary occlusion pressure. Consequently, patients with severe cardiorespiratory instability, who cannot be turned, and patients with pressure sores with broken skin benefit most. The additional ability to control the temperature of the immediate environment is an advantage in hypothermic patients and those with large surface area burns. Any exudate from the skin is adsorbed into the silicone beads on which the patient floats. This drying effect is particularly useful in major burns (although it must be taken into account for fluid replacement therapy). The air fluidised bed also has a role in pain relief.